Texas Instruments TMS320C6745 DSP - MMC;SD Mode Multiple-Block Read Operation

ARG HIGH
RCA ADDRESS HIGH
STATUS 0
NEXT DATA BYTE
DATA RX
MMC controller
register content
MMC controller
register
RCA ADDRESS LOW
ARG LOW
SEL/DESEL. CARD
COMMAND
Select one card with relative
card address (RCA) while
de−selecting the other cards.
SET_BLOCKLEN
BLK ADDRESS LOW
BLK ADDRESS HIGH
COMMAND
ARG LOW
ARG HIGH
READ_MULT_BLOCK
COMMAND
Load starting block address
into the high and low argument
registers. Load block
length register with the block
length value. Start the operation by
Is CRCRD = 1?
Is DRRDY = 1?
loading a READ_MULTIPLE_BLOCK
command into the command
register.
Check TOUTRD bit to verify
that the read operation has not
timed−out. Check CRCRD bit for
any read CRC errors. Check DRRDY
to see if a new byte is in the data
STOP_TRANSMISSION
COMMAND
Terminate the multiple−block
read operation.
Is TOUTRD = 1?
receive register.
Procedures for Common Operations www.ti.com
1122
SPRUH91D–March 2013–Revised September 2016
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Multimedia Card (MMC)/Secure Digital (SD) Card Controller
14. Read n bytes (depends on setting of FIFOLEV in MMCFIFOCTL: 0 = 32 bytes, 1 = 64 bytes) of data
from the MMC data receive register (MMCDRR) and return to Step 10.
15. Use MMCCMD to send the STOP_TRANSMISSION command.
The sequence of events in this operation is shown in Figure 25-16.
Figure 25-16. MMC/SD Mode Multiple-Block Read Operation